为了满足空间反射镜温度适应性好、结构紧凑的要求, 采用有限元分析方法, 以超低膨胀系数玻璃空间反射镜(355mm)为支撑对象, 设计了一种背部双脚架柔性支撑结构。首先研究了双脚架支撑的基本设计原则, 从自由度角度分析了双脚架支撑结构相对背部3点支撑结构的优势。然后针对支撑结构尺寸参量、柔性铰链结构尺寸参量对面型精度的影响进行了仿真分析和优化设计, 提出支撑脚延长线交点位置应作为背部双脚架支撑的关键设计参量, 与粘接位置分别设计。结果表明, 优化设计后的背部双脚架柔性支撑结构温度适应性好, 能够有效卸载温度变化引入的附加载荷, 同时具有较好的支撑效果和动态刚度; 反射镜支撑后面形精度均方根值为3.68nm, 组件的1阶频率达到123.41Hz, 满足设计要求。该研究对未来背部双脚架支撑结构设计具有借鉴意义。

To satisfy the requirement of thermal adaptability and limited space, a kind of bipod flexure mounts for space reflector (355mm) made of super low expansion coefficient glass was designed by finite element analysis (FEA) method. Firstly, the basic design principles of bipod flexure were studied. The advantage of bipod structure, compared with three points backside structure, was discussed from the view of freedom. Secondly, simulation analysis and optimization design were carried out for the influence of dimension parameters of support structure and flexure hinge on the surface figure accuracy. The intersection position of supporting foot extension line should be the key design parameters and the bonding position should be designed respectively. The results indicate that backside bipod flexure mounts after improved design has fine thermal adaptability and can effectively discharge the load caused by thermal variation, and has fine supporting ability and dynamic stiffness at the same time. root mean square of surface figure accuracy reaches 3.68nm, after reflection mirror mounting, and the first order frequency of assembly is 123.41Hz. The data can meet the design requirements. This study can supply the meaningful reference for future structure design of backside bipod mounts.